Digital mammography vendors wait for FDA clearance

Although GE Medical Systems was the only company at the American College of Radiology’s National Conference on Breast Cancer this month that sells digital mammography units in the U.S., other exhibitors showing their systems have already asked for federal approval or are moving in that direction.

Both premarket approval and 510(k) clearance are being pursued by manufacturers while they await further direction from the FDA.

According to doctors at the ACR conference in San Francisco, the demand for digital mammography will not fade while these companies are waiting.

“The next obvious advance (in breast imaging) is going to come from digital mammography,” said Dr. Daniel Kopans, director of breast imaging at Massachusetts General Hospital and moderator of a technology roundtable at the conference.

Fischer Imaging displayed its Mammotest and Senoscan systems. The fully digital Senoscan is not yet being sold in the U.S., but the company is getting ready to submit a 510(k) to the FDA. It has been sold in Europe.

Fuji has begun clinical trials in the U.S. for CR digital mammography. Fujui company officials say clinicians who use Fuji systems can change the cassettes and imaging plates in their current systems, activate the algorithms already in the readers, and use them for breast imaging. Fuji still needs FDA approval for its system. The company has not yet decided whether to pursue a PMA or 510 (k).

GE Medical Systems showed off the Senographe 2000D, the full-field digital mammography that GE sells for hard-copy read only. GE is hoping to get approval for the system’s softcopy read by the end of this year. GE has sold 15 of these units in the U.S. and another 25 in Europe, according to its March sales figures.

Imaging Diagnostic Systems highlighted its Computed Tomography Laser Mammography (CTLM) system, which carries an integrated array of 168 detectors and a laser beam that rotates around the breast to create 3-D tomographic images without compressing breast tissue. The FDA started reviewing a progress report from the CTLM’s clinical trials at the end of March (SCAN 2/29/00).

Instrumentarium Imaging’s full-field digital Diamond mammography system made its debut. The Diamond was submitted to the FDA for 510(k) clearance in March. The system uses the company’s 3-D tuned aperture computed tomography, known as TACT. With TACT, seven flat images are obtained from different angles during a standard stereotactic x-ray tube sweep. When the slices are viewed on the workstation, points of interest can be reconstructed in 3-D.

Siemens displayed the Mammomat 3000 Nova system and add-ons that go with it. The 3000 model is a platform for full-field digital technology. Siemens is collecting data from tests on the system at a few clinical sites, including the Medical College of Virginia, and may pursue premarket approval next year, given current FDA recommendations.

Trex said it is going through the PMA process for full-field digital offerings after the FDA rejected a 510(k) application. Trex displayed digital capabilities on the M-IV at the conference. The company also exhibited its Elite mammography systems.

In addition to digital mammography, computer-aided detection may be the next step in breast imaging, according to Kopans.

“The computer enables us to do things we haven’t done before,” he said.

These capabilities include digital tomosynthesis, which allows a computer to take images from multiple angles, slice the information, and build the image back up again; dual-energy subtraction, whereby clinicians image calcifications more clearly by taking high- and low-energy images and subtracting them from each other; and the use of contrast agents.

R2 Technology and CADx Medical Systems were among companies that displayed computer-aided detection systems at the conference.